Why does apple slow down old devices?

I am so upset with apple because i have an iPad 2 that i literally rarely ever used and is pretty much new but yet its so slow. This started after i updated my ipad i hadn't updated my iPad for about 2.5 years and then all of the sudden it just completely slowed down! I am a die hard apple fan i've had everything apple for about a decade because I thought and always believed that they made superior products. But now i am realizing that their products are not made to last! I am not the only one with this problem either my sister has a white apple macbook and same thing has happened to her! Her macbook is horribly slow and just a terribly laptop now she has only had it for about 3 years and it is literally worthless now. i don't get it apple! Why do you do this to your customers! You create nice products that only seemed to be temporary you are ripping us off! Why now i don't even want to buy an iPhone Im trying to look for alternatives! Please answer my question! Does anyone else have this issue with their apple products? This seems so suspicious! I even refuse to update my macbook air because i am afraid apple is going to slow it down!